That’s what the nurse told me when reviewing the results of my annual health risk assessment at work. She was being kind. In one year I’d gained seven pounds, my waist had expanded inch and my body fat increased a full percentage. “Yeah, I’ve had a lot of weddings to go to,” I said, as if one month of excess could account for the gains.

The truth was despite exercising just as much as the year before (I’m on a bike racing team), I had been feeling the extra weight creep on for months. At 5’6” and 140 pounds I was nowhere near overweight, but I was past the point of feeling comfortable in my own skin—my bike shorts were starting to resemble sausage casings. I suspected that overtraining was partly to blame because constant muscular fatigue had caused me to cut back on the amount and intensity of my exercise, but I had taken steps to correct that and the extra weight remained. That meant there could only be one other possible culprit: my diet.

So when Mark Macdonald, creator of Venice Nutrition and author of the New York Times bestseller Body Confidence, offered me a chance to test-drive his program I jumped at the chance. And by “jumped” I mean I figured I would follow his advice for a few weeks, drop some weight and then go back to my regularly scheduled programming. Because really, what could I have been doing wrong? I'm a health writer so I knew to fill my plate with fruits and veggies and whole grains. I thought I was probably just eating too much avocado or peanut butter. Besides, dieting works, but it's not sustainable. I'd read enough weight loss research studies to know that. Still, I needed to do something to get back on track, so I scheduled a call with Mark for after my sister's mid-October wedding.

Mark seemed stoked to work with me. I don’t normally use words like stoked, but how else do you describe a guy who says he’s “fired up to get you dialed in!” and signs all his emails with “Huge Hug.” He was so genuinely sweet and excited that I couldn't help but get excited, too. I started actually looking forward to dieting and began hoping that it really would work.

During our first phone call on October 25th Mark explained the theory behind the Venice Nutrition plan, which is based on blood sugar stabilization. Weight loss, said Mark, has just as much to do with hormones as calories. Here’s why:

Blood sugar is controlled by the pancreas. The two main hormones in the pancreas are insulin and glucagon. If your blood sugar drops below 80 mg/dl, your pancreas over-releases glucagon, which causes your body to breakdown stored glucose and amino acids (muscle) to boost blood sugar. If it gets too high (above 120 mg/dl), your pancreas releases too much insulin, which triggers your body to store all nutrients (often as fat) in an attempt to lower blood sugar.

Blood sugar. It was something I had only associated with diabetics. But when I started thinking about it, I realized that I often had late-afternoon crashes. Crashes so bad I would get dizzy, flushed and nauseous. Crashes that I often ignored because I was too busy to eat. However, as I explained to Mark, if I waited long enough the hunger pangs would pass. Yeah, that's because your body broke down muscle tissue to get the nutrients it needed, he replied. Oh.

So how could I keep my blood sugar balanced and my body primed to release and burn fat? There were three things I needed to do, said Mark.

Eat within 30 minutes of waking and then every three to four hours after that—including within an hour of bedtime.

Make sure every meal and/or snack is made up of roughly 40 percent protein, 35 percent carbs and 25 percent fat (protein triggers glucagon, carbs trigger insulin and fat slows digestion). Research shows that sticking to ratios like these can help you eat more and still lose weight.

Eat a specific amount of calories per meal—your body can only process a certain amount of food at once. You should feel hungry, but not starving, when you begin a meal and satisfied, not stuffed, when you finish.

Because I follow a fairly rigorous training schedule, Mark didn’t suggest a workout routine, but he did have a few more recommendations: drink a ton more water, take a multivitamin and fish oil supplements daily and swap my regular sugar-heavy sports drink for a mixture of Proto Whey protein powder and Hammer Nutrition Recoverite.

After the phone call, there was just one more step: Become a member of Venice Nutrition, the web tool that develops your personalized plan (It's available to anyone for just $20/month). After filling out a questionnaire, I was given my allotted calories per meal (250), meal recommendations based on the foods I like (everything; perhaps that’s the problem), recipes and access to an awesome food and exercise log that makes it easy to tweak the recommended meals or come up with my own.

Over the next weekend I dropped a small fortune at GNC and the grocery store getting ready. Mark clearly did not live in New York City when he created this diet. I probably spent close to $300 getting all the necessary food, supplements and supplies (like a food scale). It was a shock to say the least, but I had made a commitment, I told myself, and there was no turning back now.

On Monday, I hit the ground running...and ran right into a wall. Since I like healthy foods, I figured I’d just be eating less of them. Boy was I wrong. I had a blood sugar crash Monday evening and by Wednesday I had run out of food and needed to go back to the grocery store. But the worst part was, despite eating straight through my stash, I was still hungry! If carb withdrawl is a real condition, I was in it. I spent the rest of the week irritable, foggy and dragging ass through my workouts.

By Friday I wasn’t feeling great, but I had managed to survive the week without cheating. No small feat considering it included Halloween, a photo shoot filled with yummy catering and Bagel Wednesday—the mysterious phenomenon in which leftover bagels and cream cheese appear in our office kitchen at the exact moment your willpower begins to wane.

I was convinced Mark needed to increase size of my meals. However, when I spoke to him on the phone he didn’t agree. Mark explained that until I got to a certain level of body fat (usually under 14 percent for women), increasing meal frequency rather than meal size is more likely to keep my metabolism humming. He took a look at my journal and recommended making a few changes:

Eat more full meals. I was eating half-meals or snacks mid-morning and mid-afternoon, but with my training schedule I needed more sustenance.

Eat more high-quality foods—especially before and after workouts. A bar before biking and a protein shake afterward wasn't going to cut it.

Drink my sports mix during workouts. Because I was only doing 60-minutes of cardio and strength work at a time during this phase of my training I was just drinking water during my workouts. However this was making me ravenous afterward, especially on days I had double sessions (training in the morning and at night).

“All of this takes effort but it’s worth the effort,” Mark told me. “You have to put the time in if you want to be your best.”

Keeping that in mind, I spent the next month getting "dialed in" as Mark would say. I went shopping at Costco and stocked up on so much chicken, fish and frozen produce it barely fit in my fridge. I started spending part of every Sunday planning and cooking meals I knew I would look forward to eating (turkey bacon, egg, and cheese wrap for breakfast? Yes, please!) And I began taking more time each morning to pack enough meals to get me through a workday. Once I got into the groove I was eating about seven meals a day. And you know what? A funny thing happened: The weight started coming off. First a pound. Then two.

By Thanksgiving I was down to 133.

But what really impressed me were all the unexpected benefits. My eyelashes grew, my face cleared up (I no longer needed the two prescriptions I had been using to keep breakouts at bay), my muscles rebounded quicker between workouts, my bloating disappeared (in fact my stomach was now always completely flat) and, most miraculously, my chronic migraines all but vanished. I even did a routine VO2 max test, which gauges aerobic capacity, and found that not only was I getting fitter, but my calorie and fat burning levels had skyrocketed compared to earlier in the year.

I was content with my results and heading into the holidays didn’t expect to lose any more weight. After all, I weighed around 133 in college when I was in the best shape of my life. So I unwound a bit and let myself eat whatever I wanted during my weeklong Christmas vacation. The food was delicious, but I have to admit, I felt like total crap. My stomach hurt, my head hurt and my face was a splotchy mess. I returned to New York eager to get back on track and hopped on the scale to see how much damage I had done. Curiously it read 132—the same weight I was before I left.

Realizing that I could go completely overboard for a week and still maintain my weight gave me permission to loosen the reins a bit. Even Mark recommends one "cheat meal" a week, so I told myself that if I could eat on plan 80 percent of the time, I would be fine. Although I hadn't really been feeling deprived on this diet—or like I was on a diet at all—this allowed me to dine out, eat ice cream or grab a drink with friends whenever I wanted to without feeling guilty. Best of all, the diet still worked.

Over the next month I continued to watch my body change—my butt shrank, my arms gained definition and my abs returned. My coach commented on the transformation and three of my teammates were inspired to join Venice Nutrition. When I went to get my body fat measured again, the results amazed even me. After less than three months on the Venice Nutrition plan, I had lost 10 pounds and shed 7.1 percent of my body fat. I was down to 14.7 percent.

I've been thinking a lot about what made the difference for me. Yes my diet has changed—I still eat the same foods I used to but in different ratios (lots more protein, less carbs) and different quantities (bigger snacks, smaller meals)—but lots of people make dietary changes that don't stick. The bigger factors, I think, were motivation, support and accountability. Once I realized that my diet may be holding me back athletically, I wanted to get it right. Having a patient boyfriend who wouldn't get mad when I'd spend a half hour trying to figure out what take-out I wanted to order (only to decide that I'd rather go buy food at the supermarket and cook instead) made it easy not to cheat. And having Mark regularly check my food log kept me on track.

I frequently write about how food can transform your health, but it's really amazing to experience it first hand. If you've been thinking about making a change, do it. If you start today, who knows where you'll be when your next health assessment rolls around.